1. Field of the Invention
This invention pertains to an imaging element for use as a recording element and a process for preparing the recording element from the imaging element. In particular, this invention relates to a photosensitive imaging element having a photoluminescent tag disposed therein. More particularly, this invention relates to a photosensitive imaging element for use as a printing form, and a process for preparing the form from the element.
2. Description of Related Art
Polymer products are used as components of imaging and photosensitive systems and particularly in photoimaging systems such as those described in “Light-Sensitive Systems: Chemistry and Application of Nonsilver Halide Photographic Processes” by J. Kosar, John Wiley & Sons, Inc., 1965 and more recently in “Imaging Processes And Material—Neblette's Eight Edition” edited by J. Sturge, V. Walworth and A. Shepp, Van Nostrand Reinhold, 1989. In such systems, actinic radiation impinges on a material containing a photoactive component to induce a physical or chemical change in that material. An image or latent image is formed which can be thereby be processed into a useful image forming a recording element. Typically actinic radiation useful for imaging is light ranging from the near ultraviolet through the visible spectral regions, but in some instances may also include infrared, deep-ultraviolet, X-ray, and electron beam radiation.
Although the polymer product itself may be photoactive, generally a photosensitive composition contains one or more photoactive components in addition to the polymer product. Upon exposure to actinic radiation, the photoactive component acts to change the rheological state, the solubility, the surface characteristics, refractive index, the color, the electromagnetic characteristics or other such physical or chemical characteristics of the photosensitive composition as described in the Neblette's publication supra.
Polymer products are particularly useful in photopolymerizable systems such as disclosed in Chapter 7 of the Neblette's publication supra. Such photopolymerizable systems typically have at least one addition polymerizable monomeric component having one or more sites of terminal ethylenic unsaturation, and one or more polymers as a binding agent. Frequently the binding agent is a polymer, or simple polymer blend, i.e., an intimate mixture of two or more polymers. During imaging exposure, the monomeric component polymerizes and/or crosslinks to form a polymer or polymer network in which at least some of the polymeric binding agent is entrapped thereby rendering a change in the physical or chemical characteristics, that is, typically photohardening or insolubilizing, the exposed area or areas.
Some examples of imaging systems include photopolymer and resist systems for use as printing plates, pre-press proofs, and resists in circuit board and chips; and press printing systems, such as lithography, gravure, letterpress, flexography, and screens, for use in press printing and circuit board printing. For each end-use application of the polymer products a plethora of imaging elements exist due to the number of manufacturers as well as the variety of products provided by each of the manufacturers to address particular needs in end-use situations. Any one end-user facility may have a number of imaging products available to meet their and their customer's needs, but it may be difficult to monitor consumption and appropriate process conditions to convert the imaging product into desired recording material. From an end user's standpoint, it is desirable to be able to identify the imaging element should it become separated from its packaging. From the manufacturer's standpoint, when assisting the end-users and/or accepting a returned imaging product it is desirable to verify that the imaging product is in fact one made by the manufacturer, not from another manufacturer, and not a counterfeit product. Thus it is desirable for users to be able to authenticate the identity of the imaging element.
Furthermore, each imaging element typically undergoes a process of multiple steps on one or more different devices that are used to convert the imaging elements into useful recording product. Devices used include, for example, actinic radiation exposure units, laser-radiation exposure units and imagers, processors for removing selected composition material with heat or with a solution, processors for developing latent image with heat or with a solution, and lamination units for forming assemblages with the imaging element or other supports. The setup for each device can be complex and dependent upon the particular variety of imaging element being worked on. Each step in the process of forming recording elements for imaging element involves multiple parameters that need to be set appropriately to extract the optimum performance of the imaging element and create the desired recording element that satisfies the end user's needs. Thus, it is desirable to not only identify the imaging element, but also to use this identification information to direct the establishment of the parameters in the variety of devices used in the imaging process automatically without the need for human intervention.